1. Field of the Invention
The field of the invention is processor retention devices, or, more specifically, low profile computer processor retention devices and computers configured with low profile computer processor retention devices
2. Description of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today's computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.
Computer systems today are increasingly more computationally powerful due in large part to technological advances in processors. Current processors, however, generate a relatively large amount of a heat. Heat, if not efficiently dissipated, may cause errors and failure in a computer over time. Heat generation by processors and heat dissipation are important operational characteristics of a computer. Heat sinks are presently employed to dissipate heat generated by computer processors. The heat sink may be in physical contact with a heat spreader of a processor or may be in contact with a thermal grease applied to a heat spreader. The heat spreader is typically installed directly on an organic substrate of the processor. Physical contact between the heat sink and the heat spreader is effected through use of fasteners of a retention mechanism. A retention mechanism holds the processor in a socket on a motherboard and enables the heat sink to come into direct contact with the processor.
At the same time computer processors are increasing operating speeds and heat generation, size requirements for computers are decreasing. That is, computer enclosures are decreasing in size. Heat generation in a smaller enclosure has a greater effect on computer system components. In addition, efficiency of heat dissipation is greatly reduced due to reduced air flow volume in and through the enclosure.
Current retention mechanisms that hold processors into sockets and couple heat sinks to heat spreaders of the sockets are not optimized for smaller computer enclosures. For further explanation, FIG. 1 sets forth a line drawing of a cross-sectional view of a retention mechanism of the prior art. In FIG. 1, a computer processor consisting of an organic substrate (220) and a heat spreader (322) is installed in a socket (216). A retention frame (210) is connected to a housing (308) and is retaining the processor by direct contact on the heat spreader (322). Two spring-loaded screws are used to attach a heat sink (202) having a number of fins (204) to the heat spreader (322).
The heat sink (202) in FIG. 1 includes a number of fins (204). The surface area of the fins (204) is a critical variable to the effectiveness of the heat transfer. Increasing the surface area of the fins (204) increases the effectiveness of heat transfer and vice versa. However, with the ongoing decrease in enclosure size and an increase in computer processor and other computer component size, the surface area of heat sink fins (204) is jeopardized in current computers. An example of a computer having a smaller enclosure is an IBM Blade Server. The Blade Server is approximately 29 millimeters tall. With a processor installed and with the retention mechanism increasingly becoming larger, the heat sink fin (204) height has been reduced over time. In some cases, the heat sink fin heath is reduced such the surface area of the fins does not provide for a practical thermal solution for dissipating processor generated heat.
In addition to heat sink fin surface area, the geometry of the base of the heat sink (202) is another critical variable to the effectiveness of the heat sink (202). A heat sink with a large base and a continuous surface without steps or cutouts has better heat flux through the base then a heat sink of the same material with irregular geometry such as a pedestal from the base that extends downward to make contact with the heat spreader of the processor. In the example of FIG. 1, the heat sink (202) has a pedestal-type base. Current trends in processors and their associated hardware are driving more irregular shaped bases for the heat sinks and are therefore inefficient thermal solutions.